is 2 621893 - 1
has 187209 decimal digits
takes 0.009 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L05CE89219A40A945double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26747.779870.1493%1275000408000000.07555.9359%47.855371.9212%1.7719%
PrimeNet2400.000050.0000%60002200000.000420.5994%0.000460.2997%10.2997%
GPU722440.000054.5455%110003600000.000715.6187%0.000761.6449%7.0994%
Difference+23+47.7798+15.6038%+1264000+40440000+0.0749-9.6828%+47.8547+10.2763%+10.2763%

Known prime factors (1 factor, 77.4 bits, 0.01244526% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
6218931988734965429708186657532477.396159893660599951132
22 × 2111 × 18935772216953
2014-03-3021111893577221695391,95922,73042,453

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2000-12-31T00:00:00Alex Kruppav4_computers200040000---8.96776e-5--0.110%
2001-01-14T00:00:00Alex Kruppav4_computers1000004000000---0.007--2.582%
2002-05-11T00:00:00ANONYMOUSv4_computers163841638400---0.002--1.212%
2002-06-29T00:00:00ANONYMOUSv4_computers327683276800---0.005--1.827%
2002-09-29T00:00:00ANONYMOUSv4_computers655366553600---0.009--2.583%
2003-05-19T00:00:00ANONYMOUSv4_computers13107213107200---0.018--3.466%
2011-07-10T12:45:00Jocelyn LaroucheManual testing369019369019---0.008--1.474%
2011-08-31T00:06:00Jocelyn LaroucheManual testing615032615032---0.014--1.855%
2012-06-19T02:41:00Jocelyn LaroucheManual testing621937621937---0.014--1.864%
2012-08-01T01:16:00Jocelyn LaroucheManual testing12437861243786---0.027--2.464%
2013-10-20T13:06:00David Campeaui5-2500k127500040800000---0.076--5.936%
2016-03-17T18:49:51alpertronManual testing10000003000000012---0.057--5.483%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2001-04-15T00:00:00ANONYMOUSv4_computers21256--0.015--
2001-10-20T00:00:00ANONYMOUSv4_computers21257--0.031--
2003-11-08T00:00:00ANONYMOUSv4_computers21258--0.062--
2008-10-10T22:23:00Sturle Sundebach.ifi258259--0.062--
2008-10-10T23:07:00Sturle Sundebach.ifi259260--0.123--
2011-01-02T22:12:00Sid & AndyToy_Soldier260261--0.247--


ECM factoring results:

Old Calculation Method

Total ECM effort:8.460 GHz-days
Estimated T-Level:25.344
DigitsB1CurvesCompleteFacMiss
2011000322 / 1003.2203.931%
2550000322 / 2801.15031.599%
3025000044 / 6400.06993.351%

New Calculation Method

Total ECM effort:8.460 GHz-days
Estimated T-Level:25.344
DigitsB1CompleteFacMiss
201100012.6340.000%
25500001.34126.168%
302500000.10789.841%
3510000000.00799.298%


ECM Summary

B1B2factorcurvesGHz-days
10.00000e+0
5000050000002784.723
25000025000000443.738


Lucas-Lehmer results:
No L-L results for M621893


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-27T12:55:42Oliver KruseGTX-0
198873496542970818665753
BC654F0A13CE41__no
2017-10-13T12:52:58Oliver KruseThreadripperBC654F0A13CE41__no
2017-12-15T19:30:13ATHec2-1xf
198873496542970818665753
BC654F0A13CE41__no
2020-04-19T16:36:58Oliver KruseAddPrpType5
198873496542970818665753
94629206FA7692__no


P-1 factor-bounds graph:
B1 = 1275000, B2 = 40800000 (P-1 stage 2)
B1 = 1000000, B2 = 30000000 (P-1 stage 2)
B1 = 1275000 (P-1 stage 1)
B1 = 1243786 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 621937 (P-1 stage 1)
B1 = 615032 (P-1 stage 1)
B1 = 65536, B2 = 6553600 (P-1 stage 2)
B1 = 369019 (P-1 stage 1)
B1 = 100000, B2 = 4000000 (P-1 stage 2)
B1 = 32768, B2 = 3276800 (P-1 stage 2)
B1 = 131072 (P-1 stage 1)
B1 = 16384, B2 = 1638400 (P-1 stage 2)
B1 = 100000 (P-1 stage 1)
B1 = 65536 (P-1 stage 1)
B1 = 32768 (P-1 stage 1)
B1 = 16384 (P-1 stage 1)
B1 = 2000, B2 = 40000 (P-1 stage 2)
B1 = 2000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2020-04-19T16:36:58+00:00